Author Topic: Archive 15  (Read 3759 times)

Richard

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Archive 15
« on: May 03, 2012, 09:55:21 am »









AB Power Plate Poor Performance      Archive   15
I would not have recommended Adler Barbours Power Plate in an eight cubic foot box as it lacks the surface area to remove enough heat in a warm climate. When you report, the unit run continuously with the analog thermostat set on 3.5, This indicates there is a refrigerant problem and not a problem with power plates efficiency. Recommendation: Check the last numbers on paper label on top of thermostat plastic cover, as this will indicate the compressors speed. Maximum speed of 3500 rpm will be indicated by the number R1500. If this number is smaller than this please advise. If the R number is smaller than 680 or the number is missing an accurate ammeter reading is needed to see if the system has the correct amount of refrigerant. Is there frost on return line returning outside the box toward the compressor? Because there is a choice of evaporators and condensing units today with most ice box conversion units it is not uncommon to assemble a system and find an incorrect refrigerant charge. If the refrigerant charge is low the installer is blamed for not connecting the line properly, and warranty is rejected.

Sea Frost BDXp Freezer Bin System
Richard: Until I get the book in the mail, could you advise me on your general assessment of the Sea Frost BD xp system with the freezer bin? The expected installation location is well insulated. The boat location is Houston, TX. Thanks.

Old Super Cold Machine
If there is no electronic module you have a compressor motor with brushes. Current draw of 7.8 amps would indicate the compressor is working well and under a load. Line Iced up within two feet of compressor indicates too much refrigerant or contaminated R12 refrigerant. Try removing a small amount of refrigerant, then run for 20 minutes, if there is frost outside box on line remove a very small amount again. Repeat these steps slowly until frost is not present outside box. A properly serviced unit will have frost covering 100% of evaporators surface area. If reducing the frost outside box also reduces frost on evaporator refrigerant is contaminated and must be evacuated with a refrigerant vacuum pump before re-servicing with only R12 refrigerant. If and when this compressor will no longer run the brushes are worn out as well as the evaporator, so at that point buy a complete new system.

Selecting a 12 Volt Refrigeration Unit
Sea Frosts BDxp condensing unit with a BD80 compressor has 30% more capacity at the higher evaporator temperatures than units with BD50 compressors. The new BD80 compressor now offers greater efficiency for large size boxes requiring daily heat removal from 12,528 to 19,200 Btu. These daily Btu capacities will vary as evaporator temperature changes above or below +10 degrees F. It is desirable to select a system that satisfies the daily Btu requirement with only a 50% duty cycle. I have not tested Sea Frosts BDxp or their Bin evaporator box, but I have been present during extreme tests of the BD80 compressor at another company. Before I could recommend a system for a boat operating out of Houston I would need to know;amount of insulation and its age, size of box or boxes, what box temperatures are you looking for? If you watch the Slide Show on my web site you will know what I need to know to help you.


Mr. Kollman I went to the boat last night and checked the thermostat there was no plastic lable on the thermostat other than Adler Barbour's name. Additionally there did not appear to be any type of resistor in line with the thermostat. There was about 1" of frost on the return line outside of the box. Thank you for your assistance Bob


Also i was incorrect about the size of the box it is more like 6 cu ft. Bob

More information
Richard: The box is approximately 6 CF. The type of insulation is unknown, but is a minimum of six inches on the sides and bottom and 4 inches on the top. I would like to be able to freeze cold enough in the bin to have ice cream (10-20 degrees) and use the rest for refrigeration (34 to 40 degrees). I am not sure if the bin is better or to have two opposing plates for a freezer section and a spill over for refrigeration. Should I not waste money on the water cooling option given the reliability issues? Thanks.

Selecting refrigeration begins with the Compressor
A BD80 compressors over capacity would mean less efficient this was the problem with the old BD fixed speed compressors when installed in a small box, they consumed more energy than was required. If your 6 cubic foot box has insulation four inches thick a BD80 compressor is overkill. If the complete box were to be a freezer then the BD80 would be a good choice with two plates. I would recommend for your application cruising in the Houston area Frigoboat Capri 50-SSC and their 304B evaporator, if evaporator will fit in the box. This BD50 Compressor unit has automatic speed control with soft start protection that is needed in hot climates. I do not recommend water cooling of systems with small BD compressors as water cooling compromises reliability.

Power Plate System Poor performance.
There is a resistor in one of the wires connected to thermostat but it is so small it is hard to find but forget it for now. The flag you raised is the one inch of frost on line outside the box. Frost Line is an important indicator of refrigerant volume on this type system. I need a better description of frost on line between evaporator and compressor. These lines are normally 10 to 15 feet long with excess line coiled nere compressor. I need to know how much of this line has a film of frost on it.


The Line is 15 feet. There is about 3 feet of rubber insulation on the line coming out of the refrigerator. The 1 inch of frost is immedately behind that rubber insullation. Bob

Power Plate in Six Cu Ft Box
I was assuming that this was a refrigerator with a freezer section. If you want the complete box to be a freezer the power plates surface area is too small to handle a six cubic foot Freezer box. Even if the proper evaporator were selected for the BD50 condensing units maximum output it would still be too small for latitudes south of 40 north. I can not explain why the compressor runs continuously unless it is a freezer thermostat Adler Barbour C1502JR or the sensing tube is not connected properly or compressor speed is too slow. If there is no resistor in thermostat wire the compressor will run at slow speed, I believe it should have a 1500 ohm resistor. To find the resistance, in this circuit turn off circuit breaker and make sure thermostat is set to cooling. Disconnect the thermostat wires at compressor panel and check resistance of the wiring through the thermostat and boat wiring circuit. All new Adler Barbour units have a telephone plug for thermostat wire at relay panel but you can still connect to the small pins, they should be two pins side by side the other pins are open and no continuity.


Your correct this is refrigerator with a freezer section. The freezer is probably about 2-3 cu ft. I will check for the resistance this week end. The unit has 15ft of tubing. There is about 2-3 ft of insulation on the tubing coming out of the refrigerator. There is 1 inch of frost behind the insulated part of the tubing. Thanks for all your assistance. Bob


Firstbananas, Does "behind the insulated part" mean that the frost is underneath the insulation or downstream of the insulation if looking at the suction line?

Height of condenser unit
Mr. Kollman, On a catamaran, I have limited space to mount the condenser unit down low (very narrow hulls) Would it make any difference how high it is mounted in relation to the evaperator? My ideal mounting location would be about one foot above and four feet away. What is best to do with the excess tubing, coil it near the evaperator or near the condenser? Thanks, Bill